J-20 5th Gen Fighter Thread V

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Air Force Brat

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Interesting, it's the first time I know the term of this. This is the major cause of most of my crash when I started to play lock on. During landing or in flight, sometimes even during taking off.

If indeed this has occurred with the J-20, and as Dr. Song noted himself the FCS for the distant coupled canard, with delta main wing is "very complex", it most definitely explains our current "waiting period". I believe the Eng would agree, it took me some time to get a read on this bird, and get a basic understanding of what was actually going on in flight? if you note the system self checks as the bird starts and comes "on-line", the flight controls cycle and move through a tremendous range of "throw".

All that to say that like the Gripen and Raptor, this lovely FCS is very smart, but it is possible to get a "glitch" in such a complex system? now back to the PIO or supposed PIO.

The term leads one to believe it is a pilot "error" type of thing, and in the case of the Raptor and Gripen, that is not precisely true?? a true fly by wire actually has the computer "interpreting" the pilots stick and rudder inputs and "flying" the aircraft in response to the pilots control in-put. In response to the control anomaly, the pilot begins to "chase" the aircraft attempting to get it to "damp out" the obvious porpoising, his input, coupling with the FCS glitch only exacerbate an already out of control aircraft and the pitch oscillations gain in wave width and frequency.

It is the same with Sport Bikes that can be observed during very high speed, to be light on the front end, and then the bike will throw a fit and exhibit "head shake". in watching a Super-Bike race this usually occurs coming out of a corner after the rider has come back up on the throttle rapidly, the front is light, possibly off the ground, and the steering damper is set up a little loose, and you will note a very rapid oscillation of the forks and handlebar side to side.

It is very disconcerting, and while it can be "ridden through", panicking and closing the throttle may result in the bike and rider being given the "heave ho" and appearing to be thrown to the ground. The thing is to grip the tank firmly between your knees and stay on the throttle as the last thing you want is that front tire to be slammed back down to the pavement while it is fully transited to the right or left.

I will say that I never experienced that on my bike, thankfully, yes I had a very healthy respect for that thing, now my little brothers C-150 was blown back into the air and the nose was coming up and aircraft was drifting rapidly across the runway due to a gust that was prolly about 5 to 7 knots over the demonstrated crosswind capability of the aircraft? Full throttle and forward stick stopped the assent, but not the drift, as I attempted to get the left wing down, and the right rudder in to cross control, in order to arrest the drift while maintaining runway heading, my brain popped a circuit breaker do to "overload". A very ugly landing, my flying mojo is still somewhat "dinged", but thankfully the airplane and my brother were fine.
 

lllchairmanlll

Junior Member
Registered Member
If indeed this has occurred with the J-20, and as Dr. Song noted himself the FCS for the distant coupled canard, with delta main wing is "very complex", it most definitely explains our current "waiting period". I believe the Eng would agree, it took me some time to get a read on this bird, and get a basic understanding of what was actually going on in flight? if you note the system self checks as the bird starts and comes "on-line", the flight controls cycle and move through a tremendous range of "throw".

All that to say that like the Gripen and Raptor, this lovely FCS is very smart, but it is possible to get a "glitch" in such a complex system? now back to the PIO or supposed PIO.

The term leads one to believe it is a pilot "error" type of thing, and in the case of the Raptor and Gripen, that is not precisely true?? a true fly by wire actually has the computer "interpreting" the pilots stick and rudder inputs and "flying" the aircraft in response to the pilots control in-put. In response to the control anomaly, the pilot begins to "chase" the aircraft attempting to get it to "damp out" the obvious porpoising, his input, coupling with the FCS glitch only exacerbate an already out of control aircraft and the pitch oscillations gain in wave width and frequency.

It is the same with Sport Bikes that can be observed during very high speed, to be light on the front end, and then the bike will throw a fit and exhibit "head shake". in watching a Super-Bike race this usually occurs coming out of a corner after the rider has come back up on the throttle rapidly, the front is light, possibly off the ground, and the steering damper is set up a little loose, and you will note a very rapid oscillation of the forks and handlebar side to side.

It is very disconcerting, and while it can be "ridden through", panicking and closing the throttle may result in the bike and rider being given the "heave ho" and appearing to be thrown to the ground. The thing is to grip the tank firmly between your knees and stay on the throttle as the last thing you want is that front tire to be slammed back down to the pavement while it is fully transited to the right or left.

I will say that I never experienced that on my bike, thankfully, yes I had a very healthy respect for that thing, now my little brothers C-150 was blown back into the air and the nose was coming up and aircraft was drifting rapidly across the runway due to a gust that was prolly about 5 to 7 knots over the demonstrated crosswind capability of the aircraft? Full throttle and forward stick stopped the assent, but not the drift, as I attempted to get the left wing down, and the right rudder in to cross control, in order to arrest the drift while maintaining runway heading, my brain popped a circuit breaker do to "overload". A very ugly landing, my flying mojo is still somewhat "dinged", but thankfully the airplane and my brother were fine.
Do you think J20 will eventually use vector thrusting? Based on recent news, it seems like low observable AVEN is almost well developed. My guess is that WS15 will probably not be mature until at least 2020 and I do not think it is necessary to use AVEN on AL-31 series engines.
 

Air Force Brat

Brigadier
Super Moderator
Do you think J20 will eventually use vector thrusting? Based on recent news, it seems like low observable AVEN is almost well developed. My guess is that WS15 will probably not be mature until at least 2020 and I do not think it is necessary to use AVEN on AL-31 series engines.

The Eng says no, at first I wanted to argue with him, but I'm beginning to believe that he is no doubt right, I am sure they will maximize stealth, and I imagine they will use the AL-31 until the WS-15 is incorporated into the J-20, no doubt with stealthy nozzles.
 

no_name

Colonel
It is the same with Sport Bikes that can be observed during very high speed, to be light on the front end, and then the bike will throw a fit and exhibit "head shake". in watching a Super-Bike race this usually occurs coming out of a corner after the rider has come back up on the throttle rapidly, the front is light, possibly off the ground, and the steering damper is set up a little loose, and you will note a very rapid oscillation of the forks and handlebar side to side.

Like this?:

 

Blitzo

Lieutenant General
Staff member
Super Moderator
Registered Member
Nice pics via =GT over on CDF

LA2r0Qs.jpg


Ma75Eu7.jpg
 

no_name

Colonel
Is it a movable LERX behind the canard? Looks like it has the same color/material as the leading edge of the delta wing.

I'm guessing it is cover for some side way facing sensors that also acts as part of the lerx.

Or that part is made completely of durable radar absorbing material different from the rest of the plane (which may simply have RAM painted on) to break up sharp angles.
 
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